/**********************************************************************

  Audacity: A Digital Audio Editor

  AVIOContextWrapper.h

  Dmitry Vedenko

**********************************************************************/

#pragma once

#include <cstdint>
#include <memory>

#include <wx/file.h>

struct FFmpegFunctions;
typedef struct AVIOContext AVIOContext;

class FFMPEG_SUPPORT_API AVIOContextWrapper
{
public:
    enum class OpenResult
    {
        Success,
        FileOpenFailed,
        NoMemory,
        InternalError
    };

    AVIOContextWrapper(const AVIOContextWrapper&) = delete;
    AVIOContextWrapper& operator=(AVIOContextWrapper&) = delete;

    AVIOContextWrapper(AVIOContextWrapper&&) = delete;
    AVIOContextWrapper& operator=(AVIOContextWrapper&&) = delete;

    explicit AVIOContextWrapper(const FFmpegFunctions& ffmpeg) noexcept;

    AVIOContext* GetWrappedValue() noexcept;
    const AVIOContext* GetWrappedValue() const noexcept;

    virtual ~AVIOContextWrapper();

    OpenResult Open(const wxString& fileName, bool forWriting);

    virtual unsigned char* GetBuffer() const noexcept = 0;
    virtual int GetBufferSize() const noexcept = 0;
    virtual unsigned char* GetBufPtr() const noexcept = 0;
    virtual unsigned char* GetBufEnd() const noexcept = 0;

    virtual void* GetOpaque() const noexcept = 0;
    virtual void SetOpaque(void* opaque) noexcept = 0;

    virtual int64_t GetPos() const noexcept = 0;

    virtual int GetEofReached() const noexcept = 0;

    virtual int GetWriteFlag() const noexcept = 0;
    virtual void SetWriteFlag(int write_flag) noexcept = 0;

    virtual int GetError() const noexcept = 0;
    virtual void SetError(int error) noexcept = 0;

    virtual int GetSeekable() const noexcept = 0;
    virtual void SetSeekable(int seekable) noexcept = 0;

    virtual int GetDirect() const noexcept = 0;
    virtual void SetDirect(int direct) noexcept = 0;

protected:
    virtual int Read(uint8_t* buf, int size) = 0;
    const FFmpegFunctions& mFFmpeg;
    AVIOContext* mAVIOContext { nullptr };

    //! This is held indirectly by unique_ptr just so it can be swapped
    std::unique_ptr<wxFile> mpFile;

private:
    static int FileRead(void* opaque, uint8_t* buf, int size);
    static int FileWrite(void* opaque, const uint8_t* buf, int size);
    static int64_t FileSeek(void* opaque, int64_t pos, int whence);
};
